Do you want the place or not? If you want it, get to work. Write up an offer to purchase and hand it to him. Put an expiration date on the offer. If you keep lollygagging, the place will probably go into foreclosure and it will be tied up for months or years.
If you're really serious but don't know how to go about buying the place, get a real estate agent to help you for a flat fee or reduced commission.
A couple of things to keep in mind:
The place is probably under water; if so the bank will have to approve a short sale which is not real likely with prices going up.
The guy and his wife may have quite different opinions about what they want to do with the house.